1. Field of the Invention
The present invention relates to a quick connection for removably joining two pipes, and more particularly to such a connection enabling an upstream tank of oxygen to be placed in fluidic communication with a downstream pipe for distributing this gas.
2. Description of the Related Art
Such a connection conventionally comprises an upstream element, usually constituting the female part of this connection, which is connected to the tank of the gas, as well as a downstream element, usually constituting the male part of the connection, which is connected to the distribution pipe. These two upstream and downstream elements are adapted to be fitted axially, which then provokes opening of a valve slidably mounted in the body of the upstream element so as to ensure free passage of the fluid.
The female part of the quick connection is equipped with a spring-loaded lock, mounted to slide in the body of this female part, transversely to the direction of displacement of the valve. This body is pierced with a central part intended for the male element to fit therein, and at least one O-ring made of elastomer or plastics material is further provided, disposed in the vicinity of the valve.
However, this known quick connection, described in particular in EP-A-0 077 743, presents a drawback.
In effect, when the gas conveyed is subjected to sudden rises in pressure, the O-rings disposed in the vicinity of the valve of the upstream element become inflamed, which is prejudicial to the mechanical soundness of the connection and is therefore detrimental to its correct use. Moreover, the inflammation of the O-rings sometimes provokes combustion of the connection assembly, which may be at the origin of serious accidents in view of the presence of oxygen.
It is an object of the present invention to overcome this drawback by producing a quick connection or coupling which, while ensuring a reliable connection between the two pipes which are connected thereto, is particularly robust, in particular in terms of resistance to overheating, whatever the operating conditions to which the coupling is subjected.
To that end, this invention relates to a quick connection or coupling for removably joining two pipes though which oxygen flows, comprising an upstream element, particularly a female element, comprising means for connection to an upstream, pressurized gas inlet pipe, and a downstream element, particularly a male element, adapted to be fitted in each other axially thereby provoking the opening of a valve mounted in a body of the upstream element. The valve is moveable between a position of opening in which the upstream and downstream elements are coupled, and a position of closure in which the upstream and downstream elements are disconnected. The upstream element is provided with at least one O-ring, made of elastomer or plastic material, disposed in the vicinity of the valve, characterized in that this coupling comprises means for forming, both in the positions of opening and of closure, primary sealing zones which extend upstream of the at least one O-ring. The sealing zones have dimensions adapted to induce a significant reduction of the flowrate of gas flowing in the direction of the the at least one O-ring, in order to limit the overheating of the O-ring.
The invention also relates to the use of the connection as defined hereinabove for transporting oxygen.